Biodistribution and Radiation Dosimetry of Intraperitoneally Administered 124 I-Omburtamab in Patients with Desmoplastic Small Round Cell Tumors

The Journal of Nuclear Medicine

article

Milan Grkovski¹  Shakeel Modak²  Pat B. Zanzonico¹  Jorge A. Carrasquillo³  Steven M. Larson³  John L. Humm¹  Neeta Pandit-Taskar³ 

[1] Department of Medical Physics, Memorial Sloan Kettering Cancer Center;Department of Pediatrics, Memorial Sloan Kettering Cancer Center;Molecular Imaging and Therapy Service, Department of Radiology, Memorial Sloan Kettering Cancer Center;Department of Radiology, Weill Cornell Medical College

关键词: DSRCT;    omburtamab;    dosimetry;    intraperitoneal;    radioimmunotherapy;   

DOI  :  10.2967/jnumed.121.262793

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

The aim of this study was to assess the pharmacokinetics, biodistribution, and radiation dosimetry of 124I-omburtamab administered intraperitoneally in patients with desmoplastic small round cell tumor. Methods: Eligible patients diagnosed with desmoplastic small round cell tumor with peritoneal involvement were enrolled in a phase I trial of intraperitoneal radioimmunotherapy with 131I-omburtamab. After thyroid blockade and before radioimmunotherapy, patients received approximately 74 MBq of 124I-omburtamab intraperitoneally. Five serial PET/CT scans were obtained up to 144 h after injection. Multiple blood samples were obtained up to 120 h after injection. Organ-absorbed doses were calculated with OLINDA/EXM. Results: Thirty-one patients were studied. Blood pharmacokinetics exhibited a biphasic pattern consisting of an initial rising phase with a median half-time (±SD) of 23 ± 15 h and a subsequent falling phase with a median half-time of 56 ± 34 h. Peritoneal distribution was heterogeneous and diffuse in most patients. Self-dose to the peritoneal cavity was 0.58 ± 0.19 mGy/MBq. Systemic distribution and activity in major organs were low. The median absorbed doses were 0.72 ± 0.23 mGy/MBq for liver, 0.48 ± 0.17 mGy/MBq for spleen, and 0.57 ± 0.12 mGy/MBq for kidneys. The mean effective dose was 0.31 ± 0.10 mSv/MBq. Whole-body and peritoneal cavity biologic half-times were 45 ± 9 and 24 ± 5 h, respectively. Conclusion: PET/CT imaging with intraperitoneally administered 124I-omburtamab enables assessment of intraperitoneal distribution and estimation of absorbed dose to peritoneal space and normal organs before therapy.

【 授权许可】

CC BY